Advances in machine learning and signal processing enabling expansion of after-etch metrology applications

YieldStar AEI, also known as In-Device Metrology (IDM), has been enabling device overlay metrology targeting DRAM, 3DNAND, and logic applications. Recently, enhanced understanding of IDM signal and its connection to target patterns has inspired new developments in the signal-processing and machine-learning algorithms that lie at the core of IDM. This has led to expansion of IDM capabilities and its applications, namely joint tilt and overlay metrology, small target overlay applications in logic, and multiple-depth CD metrology.